It is preferable for safety driving to allow a driver to perceive the presence of a hazardous object (obstacle) around the driver, when the driver drives an automobile as an example of a moving body. Patent Literature 1 discloses a technique of detecting a line-of-sight direction of a driver, and displaying a warning indication when the line-of-sight direction of the driver is not directed toward a signal or a road sign ahead of an own vehicle. Further, Patent Literature 2 discloses a technique of guiding a line-of-sight of a driver toward an obstacle ahead of a vehicle, when the obstacle is detected by a camera or the like. Further, Patent Literature 3 discloses a technique of determining an object to be identified by a driver from among objects around an automobile, and determining whether or not a line-of-sight of the driver is directed toward the object to be identified.
It is extremely preferable for safety driving to allow a driver to securely perceive a visual perception target (identifying object) to be visually perceived (identified). However, as a premise, it is necessary to securely grasp a visual perception target that a driver should visually perceive. Further, it is also important to provide measures for allowing a driver to perceive a visual perception target, which may be overlooked by the driver.